Avalanche Forecast

Issued: Mar 7th, 2013 9:52AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Persistent Slabs.

Avalanche Canada slemieux, Avalanche Canada

Summary

Confidence

Good

Weather Forecast

Thursday night and Friday: Precipitation associated with the upper low will ease off and give place to a light, cool and dry northerly flow. Light amounts are expected on Friday with light North winds and temperatures around -6 C in the alpine. Overcast skies starting to clear in the afternoon. Freezing levels will rise to 1400 m. tomorrow.Saturday: High pressure brings dry conditions, mainly clear skies, light NW winds and freezing level rising up to 1200 m. in the afternoon. Sunday: A frontal system approaches from the North coast Saturday night weakening as it hits the interior but could leave some light precipitation amounts, slightly cooler temperatures and winds switching from the SW.

Avalanche Summary

Some sluffing in steep terrain was reported. No other recent avalanches was reported.

Snowpack Summary

Around 18 cm (30 cm in the Western part of the region) of new snow fell on top of the recent storm snow above 2000 m., on a 1-3 cm thick melt freeze crust below 2000 m. and on a sun crust on S facing slopes.  This new snow is sluffing easily in steep terrain. Soft slabs were also formed on lee terrain from Easterly winds.  In much of the region, up to 80 cm snow overlies fairly well preserved surface hoar and sun crust. This interface is still producing sudden collapse results during snow tests.  A cornice fall or an avalanche in the storm snow could definitely trigger this deeper instability. The sun and warming temperatures tomorrow afternoon and Saturday will most likely weaken the snowpack and cornices especially on S facing slopes.A strong melt-freeze crust exists at 1700 m and below and is bridging deeper instabilities. 

Problems

Storm Slabs

An icon showing Storm Slabs
  Up to 30 cm of recent snow is sitting on a melt freeze crust and has formed touchy storm slabs. It is also sluffing easily on steep slopes.
Avoid exposure to terrain traps where the consequences of even small avalanche could be serious.>Be cautious of sluffing in steep terrain.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

Persistent Slabs

An icon showing Persistent Slabs
The 80 cm deep surface hoar/sun crust weak layer could be triggered by a cornice fall or an avalanche stepping down from the storm snow. Be aware of the sun and warmth weakening the snowpack and cornices on Friday afternoon and Saturday.
Do not travel on slopes that are exposed to cornices overhead.>Be aware of thin areas at treeline that may propagate to deeper instabilites.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 6

Valid until: Mar 8th, 2013 2:00PM